[Buildroot] Python package installed without dependencies defined in setup.py

[Yegor Yefremov]

Hi Ivo,

On Thu, Feb 25, 2021 at 6:11 PM Ivo Grondman <buildroot at grondman.net> wrote:
>
> Hi Yegor,
>
> > On 25 Feb 2021, at 16:33, Yegor Yefremov <yegorslists at googlemail.com> wrote:
> >
> > You'll have to manually add all required Python packages into your
> > package's Config.in file. See package/python-flask/Config.in for the
> > reference.
>
> Thanks! It does seem a bit odd to me to have it in there, though, as:
>
> 1) It seems to defeat the purpose of using a setup.py file as that already has the necessary information on the Python package dependencies.
> 2) If the Python package dependencies of a custom Python package change, I have to make the changes in both the setup.py file (for the end user of the package in public use) and the Config.in (for myself in buildroot).
>
> Wouldn’t it be possible (maybe not now, but in the future perhaps) to have buildroot setup a virtualenv for Python during the build in which it does the installation of all the Python packages and dependencies (using pip or something) and then just moves the complete Python tree into the target? I’m being a bit short here, but I hope you know what I mean :)
>
> Any thoughts on this?

The whole stuff is not trivial. As you've seen the Python package
itself has core modeles like SSL, XML, zlib support, etc. You'll have
to find out whether your particular package needs this.

Then, many Python packages have dependencies on some C/C++ libraries
like Qt, Boost, etc., other Python packages have to be patched in
order to be compatible with BR environment etc.

All these issues/features make such an automated approach very difficult.

Take a look at BR's user manual [1] and search scanpypi.

[1] https://buildroot.org/downloads/manual/manual.html#_infrastructure_for_python_packages

Best regards,
Yegor